1 /* $OpenBSD: setenv.c,v 1.13 2010/08/23 22:31:50 millert Exp $ */
3 * Copyright (c) 1987 Regents of the University of California.
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31 /* OPENBSD ORIGINAL: lib/libc/stdlib/setenv.c */
35 #if !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV)
41 extern char **environ;
43 static char **lastenv; /* last value of environ */
46 /* OpenSSH Portable: __findenv is from getenv.c rev 1.8, made static */
49 * Returns pointer to value associated with name, if any, else NULL.
50 * Starts searching within the environmental array at offset.
51 * Sets offset to be the offset of the name/value combination in the
52 * environmental array, for use by putenv(3), setenv(3) and unsetenv(3).
53 * Explicitly removes '=' in argument name.
55 * This routine *should* be a static; don't use it.
58 __findenv(const char *name, int len, int *offset)
60 extern char **environ;
65 if (name == NULL || environ == NULL)
67 for (p = environ + *offset; (cp = *p) != NULL; ++p) {
68 for (np = name, i = len; i && *cp; i--)
71 if (i == 0 && *cp++ == '=') {
72 *offset = p - environ;
79 #if 0 /* nothing uses putenv */
82 * Add a name=value string directly to the environmental, replacing
92 for (cp = str; *cp && *cp != '='; ++cp)
96 return (-1); /* missing `=' in string */
99 if (__findenv(str, (int)(cp - str), &offset) != NULL) {
100 environ[offset++] = str;
101 /* could be set multiple times */
102 while (__findenv(str, (int)(cp - str), &offset)) {
103 for (P = &environ[offset];; ++P)
104 if (!(*P = *(P + 1)))
110 /* create new slot for string */
111 for (P = environ; *P != NULL; P++)
114 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
117 if (lastenv != environ)
118 memcpy(P, environ, cnt * sizeof(char *));
119 lastenv = environ = P;
121 environ[cnt + 1] = NULL;
130 * Set the value of the environmental variable "name" to be
131 * "value". If rewrite is set, replace any current value.
134 setenv(const char *name, const char *value, int rewrite)
138 int l_value, offset = 0;
140 for (np = name; *np && *np != '='; ++np)
145 return (-1); /* has `=' in name */
149 l_value = strlen(value);
150 if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
151 int tmpoff = offset + 1;
154 #if 0 /* XXX - existing entry may not be writable */
155 if (strlen(C) >= l_value) { /* old larger; copy over */
156 while ((*C++ = *value++))
161 /* could be set multiple times */
162 while (__findenv(name, (int)(np - name), &tmpoff)) {
163 for (P = &environ[tmpoff];; ++P)
164 if (!(*P = *(P + 1)))
167 } else { /* create new slot */
170 for (P = environ; *P != NULL; P++)
173 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
176 if (lastenv != environ)
177 memcpy(P, environ, cnt * sizeof(char *));
178 lastenv = environ = P;
180 environ[cnt + 1] = NULL;
182 if (!(environ[offset] = /* name + `=' + value */
183 malloc((size_t)((int)(np - name) + l_value + 2))))
185 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
187 for (*C++ = '='; (*C++ = *value++); )
192 #endif /* HAVE_SETENV */
194 #ifndef HAVE_UNSETENV
197 * Delete environmental variable "name".
200 unsetenv(const char *name)
206 if (!name || !*name) {
210 for (np = name; *np && *np != '='; ++np)
214 return (-1); /* has `=' in name */
217 /* could be set multiple times */
218 while (__findenv(name, (int)(np - name), &offset)) {
219 for (P = &environ[offset];; ++P)
220 if (!(*P = *(P + 1)))
225 #endif /* HAVE_UNSETENV */
227 #endif /* !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) */